1. Technical Field
The present invention relates to a radiation image sensor for capturing a radiation image in the form of image data and, more particularly, to a radiation image sensor capable of detecting an image to an edge thereof, which is applied to mammography and others, and to a making method of them.
2. Background Art
In the medical and industrial radiography, radiation imaging systems using a radiation detector instead of X-ray sensitive film have widely used in recent years. Such radiation imaging systems require no development as the X-ray sensitive film, are highly convenient, for example, in that one can check a radiation image in real time, and are also advantageous in terms of storageability of data and facility to handle.
A common radiation imaging system is configured to convert an incident radiation image into visible light or the like (including ultraviolet and infrared rays) by a scintillator, to detect the light image after the conversion by one-dimensionally or two-dimensionally arrayed photosensors, and to output an electric signal corresponding to the image data. CsI as a typical scintillator material is a hygroscopic material and has a property of absorbing water vapor (moisture) in air to dissolve. For this reason, it is necessary to provide a protective film for shielding the scintillator from the atmosphere, in order to prevent degradation of the characteristics due to the absorption of moisture.
JP 5-196742A (document 1) discloses an example of such technology in which a water-impermeable moisture barrier is formed above a scintillator layer to protect the scintillator from moisture.